Two-shaft internal combustion engine



Nav. 3, 1942. o. SCHLAEPFER TWO-SHHFT INTERNAL COMBUSTION ENGINE FiledOct. 20, 1959 4 Sheets-Sheet l INVENTOR 4 056a? 5c7yZaepj6r DMMJMMiEcLmmah ATTORNEYS 1942- o. SCHLAEPFER 2,300,977-

TWO-SHAFT INTERNAL COMBUSTION ENGINE Filed Oct. 20, 1939 4 Sheets-Sheet5 INVENTOR Osta r 565 Zae v/Zr MUM; mmuuwm ATTORNEYS Patented Nov. 3,1942 TWO-SHAFT INTERNAL COMBUSTION ENGINE Oskar Schlaepfer, Winterthur,Switzerland, as-

signor to Sulzer Freres, Socit Anonyme, Winter-that, SwitzerlandApplication October 20, 1939, Serial No. 300,341 In Switzerland June 7-,1939 4 Claims.

This invention relates to a two-shalt internal combustion engine inwhich each shaft is driven by a separate row of cylinders supplied withI supercharging air by at least one separate supercharging unit. In theengine of the invention, each row of cylinders is provided with as manyiuelpump regulating-rods, as there are supercharging groups per row, andthe rod of the cylinders belonging to one supercharging group areoperatively connected to the rod of the opposite cylinder group of theother row, so that the movement of one rod eifects correspondingmovement in the other rod. The rods are connected to a speed governorand each rod is connected to one or more limiting devices which areactuated by the pressure of the supercharging air in the superchargingunits. The limiting devices are constructed and arranged to cause theregulating rods to decrease the admission of fuel by all of the fuelpumps operated by the corresponding operatively connected rods when thesupercharging pressure of either unit falls below a predetermined value.The decrease in fuel admission to the cylinder groups of both rows theregulating rods of which are operatively connected is, accordingly,determined by the decrease in supercharging pressure in one or both ofthe supercharging units and the admission of fuel to the cylinders ofboth rows corresponds to the lowest supercharging air pressure of thetwo units.

- It is an object of the invention to interconnect the regulating rodsto the speed governor by means of a resilient coupling which permits thelimiting devices to decrease the fuel supply when the superchargingpressure is low irrespective of the action of the speed governor, and topermit the governor, at other times, to increase or decrease the iuelsupply.

The engine arrangement of the invention includes means under the controloi the speed governor for regulating the load on the engine, andparticularly for decreasing the load thereby increasing the engine speedwhen the speed of the engine previously falls as a result, for example,of the decrease in the supply of fuel. A further object of the inventionis the provision of independent supercharging units for two-row enginesin which the two rows are always equally loaded.

In the accompanying drawings:

' Fig. l is a front end view of a two-row engine having each row ofcylinders suppliedwith air from a single separatesupercharging unit;

Fig. 2 is a side view} of the engine of Fig. 1;

Fig. 3 is a top viewof theengine of Fig. 1;

Fig. 4 is a diagrammatic illustration of an arrangement of controlapparatus for an engine of the type shown in Figs. 1 to 3 embodying theinvention;

Fig. 5 is a top view of a two-row twelve-cylinder engine in which halfthe cylinders of each row is supplied with supercharging air from aseparate supercharging unit;

Fig. 6 is a diagrammatic illustration of control apparatus embodying theinvention for use in connection with an engine of the type shown in Fig.5;

Fig. '7 is an enlarged cross-sectional side view of a limiting deviceembodying the invention; and

Fig. 8 is an enlarged cross-sectional side view of a different form. oflimiting device embodying the invention.

The engine shown in Figs. 1 to 3 is a twelvecylinder two-row Dieselengine, each cylinder row i and 2 being connected to and supplied withair by a separate supercharging unit 3 and 4 comprising turbines 5 and 6driving compressors. I and 8 which force the supercharging air into theengine cylinders through the air manifolds l0 and II. The exhaust gasesfrom the cylinders which operate the turbines are finally discharged tothe atmosphere in the usual way. The air manifolds are connected topipes l3 and I4 which are connected to the limiting devices l5 and I6respectively (Fig. 4).

The limiting devices I 5 and I6 are similarly constructed. The device I6is illustrated in detail and it is understood that the description ofits operation applies to the device 15. The fuel pumps l8 and IQ of eachrow of cylinders are operated by the separate fuel-pump regulatingrods20 and 2|. These rods are fixed to the levers 22 and 23 which areinterconnected by means of the rods 24 and 25 and the double-actinglever 26. The extended end portion of the rod 20 has bifurcated members21 and 28 attached thereto, to which rods 29 and 30 of the regulatingdevices l5 and I6 respectively effect sliding contact. The upper end ofeach of the rods 29 and 30 has a stop member 35 and 36 to limit thesilding motion of the bifurcated members. Each of the limiting deviceshas a chamber 31 to which one of the pipes l3 and I4 is connected.Pressure of the gas within the chambers acts upon a diaphragm 3Bwhich'forces the rod 39 downwardly against the action of the spring 40.This action carries the'lever 4| downwardly and with it the valve 42.Any suitable fluid under pressure is admitted into the device throughthe pipe 43 and the downward action of the valve 42 permits the fiuid topass through the opening 44 and exert pressure on the lower side of thepiston 60 which is normally opposed by the action of the spring 6|. Thisraises the rods 23 and 30 and the stop members 35 and 36 from engagementwith members 21 and 28. In the positions shown in Fig. 4 thesupercharging pressure is higher than is necessary for maintaining theamount of fuel supplied to the engine by the fuel pumps.

If the supercharging pressure decreases, the diaphragm 30 rises underthe action of the spring 40. This causes the valve 42 to close theopening 44 and to permit the fluid to flow out of the chamber, therebycausing the spring 5| to force the piston 50 downwardly and bring thestop 36 into engagement with member 28. This down ward action rotatesthe regulating rods 20 and 2| in a clockwise direction and decreases theamount of fuel injected by the pumps.

The two regulating devices I5 and I6 function in precisely the same wayand either or both may serve to decrease the supply of fuel to both rowsof cylinders when the pressure of the supercharging air In either of thesupercharging units falls below a predetermined pressure.

The rods 20 and 2I are operatively connected to a speed regulator 60.For convenience, the rod 6| is connected at one end to the lever 23 andat the other end to the casing 62 of the resilient coupling 63. Thegovernor is intermediately connected to a rod 64, one end of which isconnected to a servo-motor 65 and the other end acts against a spring 66in the resilient coupling. As shown in Figs. 1 to 3, each of the shaftsI and 'II has one of the gears I2 and I3 attached thereto which drive acommon gear 14 coupled to the electric generator 15. The load on theelectric generator is controlled by means of the variable field currentapparatus I6. The rod 64 operates the valve 30 of the servo-motor 65which causes the fluid medium therein to move the piston II upwardly ordownwardly to vary the current in the field winding.

When the stop members 35 and 36 are in the positions shown, out ofpressing engagement with the members 21 and 28, the governor 60 is freeto shift the rods 6| and 04 in either direction, thereby increasing ordecreasing the quantity of fuel injected by the pumps and also varyingthe resistance of the field-regulating apparatus I6. When either of thestop members 35 r or 36 is in pressing engagement with either of themembers 27 or 20, the governor is not able to increase the quantity offuel beyond the value given by the stop 35 or 36. The governor in such acase would only act on the apparatus 16 thus reducing the load to avalue corresponding to the reduced quantity of fuel. If the load of theengine would drop below the value corresponding to the actual positionof the stops 35 or 36 the rod 64 again enters into rigid contact withthe resilient coupling 63 so that the governor reduces the fuel. The twoshafts 20 and 2I act in unison and as determined by the lowestsupercharging pressure acting upon either of the two limiting devices.

The valve 00 of the servo-motor 65 is only in the shutoff position whenthe governor 60 is in the normal position corresponding to the desiredspeed. As soon as the speed changes, the valve moves out of the shutoffposition as shown in Fig. 4 and increases or decreases the excitation inthe field of the control apparatus I6. As soon as the excitation ischanged to such an extent that the desired speed is restored, the valve00 engage a flange I26 on the rod I21 assumes the shutoff positionstopping the piston 3|.

Fig. 5 shows an engine with four supercharging units 90, 3|, 92 and 93which are similar to those Just described. The supercharging air in themanifolds 94, 35, 9B and 91 are conveyed to the limiting devices 90, 09,I00 and IN, through the pipes I02, I03, I04 and I05 respectively. Eachmanifold supplies its own group of cylinders and there are two groups ofcylinders in each row of cylinders. Each of the air manifolds suppliesair to one distinct group of cylinders.

As shown in Fig. 6, the limiting device I00, shown in section, acts in adirect manner instead of by means of a servo-motor. Each limiting deviceis the same as device I00 and comprises a diaphragm I06 acted upon bythe supercharging air pressure from pipe' I04, and a spring I01 whichopposes this action. The mode of action of these limiting devices is, inprinciple, the same as the devices illustrated in Fig. 4, with respectto the action upon the fuel pumps.

The limiting devices 98 and 99 accordingly act on the regulating rodsI08 and I09 which are rigidly connected together, and the devices I00and IM act on the rods H0 and III which are also rigidly connectedtogether. Each regulating rod is connected to and controls the action ofthe fuel pumps to one group of cylinders. These two-rod systems areconnected independently with the governor I I5 each through a resilientcoupling H6 and III. Accordingly, on a decrease of the superchargingpressure of one unit, only that rod system is withdrawn from the actionof the governor II5, for example, rod system I08 and I09 or the rodsystem H0 and III. The fuel pumps connected to the other rod system arethen always operated with the amount of fuel set by the governor.

In the limiting device shown in Fig. 7, two separate diaphragms I20 andI2I act against the springs I22 and I23 and carry the lifters I24 andI25 downwardly. The lifters are arranged to and to move the lever I28against the action of spring I23. The diaphragms are acted upon bysupercharging air from separate supercharging units through the pipesI30 and I3I. The two diaphragm units act upon a single servo-motorcomprising valve I32, fiuid inlet I33, piston I34, spring I36, leverI28, rod I31, passage I38, and chamber I39. That diaphragm which isconnected to the supercharging unit with lower supercharging pressure(in the example shown this is the diaphragm I2I), compresses the springI29 and then brings the right end of the lever I20 upwardly. The mode ofworking this device with respect to its action upon the fuel pumps isthe same as the limiting devices shown in Fig. 4.

Fig. 8 shows a limiting device in which the supercharging pressures fromtwo units are im-- posed on the diaphragm I by means of pipes HI andI42. The position of parts is for a case where the pressure in the pipeMI is greater than in pipe I42.

The air entering through the pipe I H presses the diaphragm I40 with thevalve I downwardly connecting space I46 to space I41. The air enteringthrough the pipe I42 therefore reaches the upper side of the diaphragmI50 and presses the pressure of the The lever I52 is pressed downwardlyvalve I53 with it and opening the this downwardly against spring I5I.carrying the supercharging pressure in the pipe I42 predom-' inates,then the air entering through the pipe I42 presses the diaphragm I40upwardly. The valve I45 then connects the space I58 to the space I41 bymeans of the axial hole I59 in the valve I45 through the opening I60.

When the valve I45 passes from the lower to the upper end position for acertain time, the space I46 as well as the space I58 is connected to thespace I41 so that therefore the limiting device is effective even if thesupercharglng pressure are approximately equal.

I claim:

1. The combination with a two-shaft internal combustion engine havingone row of cylinders for each shaft, gears connecting the two shafts toa common shaft and each row being supplied with air by at least twosupercharging units, each unit supplying air to a group of the cylindersof one row, fuel pump means for the cylinders of each group, a fuel-pumpregulating-rod for the fuel pump means of each group of cylinders, aspeed governor, resilient coupling means connecting the governor to theregulating rod of each group, a limiting device connected to andactuated bythe air pressure of each unit, and means operativelyconnecting the regulating rod of each group to the limiting device ofits respective group and means operatively interconnecting theregulating rod of one group of cylinders with the rod of thecorresponding group of cylinders of the other row.

2. A device for limiting the fuel admitted to an internal combustionengine havingtwo rows of cylinders, a separate supercharging air unitfor each row of cylinders and a separate fuel pump for each cylinderwhich comprises a servo-motor, means actuated by the servo-motor forlimiting the control of fuel pumps, 9. separate pressure responsivemeans connected to and operated by the supercharging air of each of thesupercharging air units, said pressure responsive means beingoperatively connected to the servo-motor whereby changes in pressure ofthe supercharging air of either unit may cause the servo-motor to changethe limiting effect on the fuel pumps.

3. The combination with a two-shaft internal combustion engine havingone row of cylinders for each shaft, gears connecting the two shafts toa common shaft and at least one supercharging unit for supplying air toeach row of cylinders, which comprises separate pump means for supplyingfuel to each row of cylinders, regulating rod means for regulating thepump means for each row of cylinders, means operatively interconnectingthe regulating rods of the rows of cylinders so that the regulating rodsso connected move in unison, a limiting device su lied with and actuatedby air from each of the supercharging units, means operativelyconnecting at least two-limiting devices to one of the regulating rods,a speed governor driven by the engine,

a resilient coupling interconnecting the governor and the regulating rodmeans permitting either limiting device of the rows of cylinders todecrease the supply of fuel independentl of the governor and saidgovernor to increase or decrease the supply of fuel but not to increasethe singly of fuel in counteraction to said limiting e ces.

4. The combination with a two-shaft internal combustion engine havingone row of cylinders on each shaft, a common shaft driven by gears fromthe two shafts and a separate supercharging unit for supplying air toeach row of cylinders which comprises pump means for supplyin fuel toeach row of cylinders, a regulating rod for regulatingthe pump means foreach row of cylinders connected to one supercharging unit, meansoperatively interconnecting the regulating rods of the rows of cylindersso that they move in unison, a limiting device supplied with andactuated by air from each of the supercharging units, means operativelyconnecting each limiting device to the regulating rod of itssupercharging unit, a speed governor for increasing and decreasing thefuel supply, a resilient coupling interconnecting the regulating rodsand the speed governor, said limiting devices, resilient coupling,regulating rods and 'govemor being constructed and arranged wherebyeither or both of the limiting devices may decrease the supply of fuelwhen the pressure 01' the supercharging air falls below a certain valueirrespective of the action of the governor.

OSKAR SCHLAEPFER.

